COMPMID-2452: Mismatches FP16 in CL InstanceNormalization

Change-Id: I8a28557370be50b2ccc9534feb9fc552c6ee5cf0
Signed-off-by: Manuel Bottini <manuel.bottini@arm.com>
Reviewed-on: https://review.mlplatform.org/c/2037
Tested-by: Arm Jenkins <bsgcomp@arm.com>
Reviewed-by: Michele Di Giorgio <michele.digiorgio@arm.com>
Comments-Addressed: Arm Jenkins <bsgcomp@arm.com>

1 files changed, 7 insertions, 12 deletions

diff --git a/tests/validation/reference/InstanceNormalizationLayer.cpp b/tests/validation/reference/InstanceNormalizationLayer.cpp
index 0e5c02aa99..ad0ac1be68 100644
--- a/tests/validation/reference/InstanceNormalizationLayer.cpp
+++ b/tests/validation/reference/InstanceNormalizationLayer.cpp
@@ -52,26 +52,21 @@ SimpleTensor<T> instance_normalization(const SimpleTensor<T> &src, float gamma,
         for(size_t c_i = 0; c_i < c_size; ++c_i)
         {
             float sum_h_w = 0;
-            //Compute mean
+            float sum_sq_h_w = 0;
+
             for(size_t h_i = 0; h_i < h_size; ++h_i)
             {
                 for(size_t w_i = 0; w_i < w_size; ++w_i)
                 {
-                    sum_h_w += src[coord2index(src.shape(), Coordinates(w_i, h_i, c_i, n_i))];
+                    float val = src[coord2index(src.shape(), Coordinates(w_i, h_i, c_i, n_i))];
+                    sum_h_w += val;
+                    sum_sq_h_w += val*val;
                 }
             }
+            //Compute mean
             const float mean_h_w = sum_h_w / (h_size * w_size);
-
             //Compute variance
-            float partial_var_h_w = 0;
-            for(size_t h_i = 0; h_i < h_size; ++h_i)
-            {
-                for(size_t w_i = 0; w_i < w_size; ++w_i)
-                {
-                    partial_var_h_w += std::pow(src[coord2index(src.shape(), Coordinates(w_i, h_i, c_i, n_i))] - mean_h_w, 2);
-                }
-            }
-            const float var_h_w = partial_var_h_w / (h_size * w_size);
+            const float var_h_w = sum_sq_h_w / (h_size * w_size) - mean_h_w * mean_h_w;;
 
             //Apply mean
             for(size_t h_i = 0; h_i < h_size; ++h_i)